Minimally invasive bone manipulation device and method of use

ABSTRACT

A novel surgical apparatus for use in orthopedic surgery procedures and a method for use is provided. The present invention includes a protective sheath which prevents fouling of the moving parts of the device by unwanted contact with surround tissue and bone. The device relates primarily to the treatment of traumatic, pathogenic, or osteoporotic bone conditions of human and other animal body systems and, more particularly, to a novel apparatus and method for manipulating the vertebral body through a less invasive, percutaneous, surgical approach.

This application is a Continuation-in-Part of U.S. application Ser. No.10/389,818, filed Mar. 18, 2003 which claims priority to U.S.Provisional Application Serial No. 60/365,026 filed Mar. 18, 2002. Theentirety of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a novel surgical apparatus for use inorthopedic surgery procedures. Particularly, the present inventionrelates to the treatment of traumatic, pathogenic, or osteoporotic boneconditions of human and other animal body systems and, moreparticularly, to a novel apparatus and method for manipulating thevertebral body through a less invasive, percutaneous, surgical approach.

2. Background of the Technology

Surgical procedures frequently require that after surgical entry hasbeen made the tissues within the patient's body must be expanded awayfrom the surgical point of interest in order to provide better accessand visibility for the surgeon. Various surgical devices have beendeveloped to assist the surgeon to displace tissue and expand theinterior cavities of the body during both open surgical procedures andless invasive surgical procedures.

Surgical procedures vary dramatically depending upon the region of thebody involved and the purpose of the surgery. The design and the use ofsurgical instruments are equally specialized and instruments whichseemingly are intended for similar purposes can be significantlydifferent from one another depending upon the exact nature of thesurgery. The use of retractors to expand an opening or create a space tofacilitate access for the surgeon during the performance of a surgicalprocedure is well known in the art. It is, however, often the case thatone tissue retractor designed for use in a particular surgical procedurewill be completely unsuitable for retraction of tissue in a differenttype of surgery.

Conventional surgical procedures, which have been employed to alleviatevertebral compression failures, involve major invasive surgicaltechniques with all of the possible negative consequences. The closeproximity of the spinal cord to damaged sections of a vertebra, whichare in need of surgical repair, presents a particularly hazardoussituation for the patient and increases the challenge for the surgeontremendously. Recent surgical innovations have been made that provide ameans of reinforcing damaged vertebra by the injection of bone cementinto the vertebral body. However, in patients suffering from cripplingeffects of osteoporosis and the possibility of compression fractures ofmultiple vertebra, there remains a need for an effective and safe way todistract the vertebral endplates so as to alleviate the compresseddisposition of the vertebral body. Such a specialized requirementdictates the need for a specialized tissue expansion device. Numeroustissue expansion devices have been developed for different surgicalprocedures but at present none are suitable or capable of adaptation soas to safely manipulate the endplates of a patient's vertebra.

U.S. Pat. No. 6,309,349 issued to Bertolero et al. discloses a typicaltissue retractor used to expand a body wall entry incision. For nearly acentury such retractors with one or more specialized modifications havebeen used to meet the particular requirements for body wall incisionexpansion in different surgical procedures. Examples of otherretractor-type tissue manipulators or expanders are disclosed in U.S.Pat. No. 6,354,994 issued to Rullo et al. and U.S. Pat. No. 6,322,500issued to Sikora et al. Retractors representative of this type arecommonly used for open surgical procedures and would be unsuited to lessinvasive surgical procedures such as, for example, endoscopic surgery.

U.S. Pat. No. 6,319,252 issued to McDevitt et al. discloses an apparatusdesigned to attach a patient's soft tissue to bone material. The designof the apparatus permits the user to manipulate an expander pin throughsoft tissue and into a position in the bone to which the tissue is to beanchored. A screw-type expander mechanism allows the diameter of thecircumferentially disposed expander pin to be increased so as to pressinto the surrounding bone. A small portion of bone is equilaterallydisplaced around the circumference of the expander pin. A very similardevice designed for a slightly different surgical procedure is disclosedin U.S. Pat. No. 6,221,107 issued to Steiner et al. The device ofSteiner et al. also employs a screw-type expander provided with specialfeatures, which facilitate the attachment of the ligament of a patientto a passage or channel created in a bone by the surgeon. Such deviceshave vary specialized uses and are incapable of selectively directingthe expansion of the surrounding tissue. Further with a screw-typeexpander the amount of expansion of the surrounding tissue is verylimited; as such this type of expansion device is typically suited onlyfor anchoring the device into the surrounding tissue.

U.S. Pat. No. 5,888,196 issued to Bonutti discloses a mechanicallyexpandable retractor for use in arthroscopic surgery. This surgicaldevice is a dual sleeve-type expander, which is designed for creating avoid in subsurface tissues using arthroscopic surgical procedures. Thistype of device is designed for movement of tissue in the repair ofcarpal tunnel syndrome. The dual sleeve expansion device of Bonutti canbe configured to have one or more expandable portions of the flexibleouter sleeve located near the tip of the device. The jointed expandableportions present an acute outermost contact surface that could easilydamage tissue with which it comes in contact and further would provide alimited point of expansion rather than a uniform area of expansion.While the expanding sleeve of Bonutti provides an expansion device thatcan be used in less invasive surgical procedures such as treatments forcarpal tunnel syndrome, it would be wholly unsuited for safe use in themanipulation of bone, particularly when employed within a vertebralbody, where the point-oriented expansion device might seriously damagealready weakened bone. U.S. Pat. No. 6,139,508 issued to Simpson et al.discloses a similar sleeve expansion device for displacing tissue in thevicinity of a biopsy site. The sleeve expansion design devices havelimited and specialized use for the temporary dislocation of soft tissuein the vicinity of a surgical site or a biopsy site. WO 02/13700 A2discloses a flexible sleeve expansion device having a deformableflexible distal portion of the sleeve for use in treatment of the spine.This device, much like balloon technology relies upon the radialdisplacement of a soft flexible sleeve, however, it does not have thebenefit of the compressed air or fluid that provides a more consistentoutward force in balloon type devices.

U.S. Pat. No. 6,358,266 issued to Bonutti discloses an active cannula orsleeve, which can be used to enlarge a channel so as to enable thepositioning of a scope or instrument or to move or relocate tissue.Bonutti '266 employs an inflatable balloon as the mechanical device toexpand the skin around a surgical entry site. The application of balloontechnology as a tissue expander has also been employed in U.S. Pat. No.6,241,734 issued to Scribner et al., which teaches the use of a balloonexpansion device employed within a vertebra for the purpose of creatinga space with the tissue. The Scribner et al. device, like otherballoon-type expansion devices are uncontrolled and multi-directional,which can lead to undesirable expansion of the bone or bone fragmentsbeing displaced in unwanted directions.

Conventionally used tissue expansion devices are each configured toprecisely meet the specific needs for particular surgical proceduresand, as such, are not readily (if at all) adaptable to meet the needs ofa different surgical procedure.

In addition to the deficiencies of the conventionally used mechanicalexpansion devices discussed above, each such device shares the commonproblem of possibly suffering mechanical interference or fouling of themechanism when tissue or bone come into contact with the internalmechanism of the devices. Such fouling of the mechanism by involvementwith tissue or bone during the insertion process, expansion process, orthe retraction process can severely limit the effectiveness of such adevice. Each possibility presents a unique problem for the surgeon usingan unprotected manipulating device, such as, for example, if themechanism becomes fouled or occluded during the insertion process, itmay fail to operate once it is properly in place. Similarly, it ispossible that during operation of the expansion mechanism, the exposedmechanism can become occluded and thus limit or fully stop the expansionprocess. Finally, if the unprotected mechanism is fouled or hung-up ontissue or bone during the retraction or removal process, the removal maybe impeded so as to require additional surgical procedures tosuccessfully extract the device.

There is therefore a need for a less invasive surgical device, which canbe precisely controlled by the surgeon to expand tissue and transmitsufficient force to manipulate bone in a selected direction or, ifdesired, in multiple directions. Further, the need exists for such adevice to have protection of the mechanism from unwanted contact withsurrounding tissues, where such contact might result in occlusion orfouling of the mechanism such that the function of the device iscompromised. None of the tissue expansion devices currently used toassist a surgeon in creating a void in tissue can fulfill thisrequirement.

SUMMARY OF THE INVENTION

The present invention provides a device and method, which can be used bya surgeon to meet the above identified need for specialized surgicalprocedures. In particular, the device of the present invention isdesigned for use as a less invasive means of controllably manipulating adamaged bone, and in particular a patient's vertebra to create a voidtherein so as to enable a surgeon to accomplish a surgical procedurewhile providing a protective member on the mechanism to avoidundesirable contact with surrounding tissue and bone.

It is therefore an object of the present invention to provide a tissueexpansion device, which can be used in open or minimally invasivesurgical procedures to selectively, in a measured manner, directionallyexpand tissue to create a void within a tissue mass, particularly withinthe interior of the bone, all the while having the mechanism of thedevice protected from contact with surrounding tissue and bone so as toensure smooth unimpeded operation.

It is a further object of the present invention to provide a tissueexpansion device that is capable of endoscopic or arthroscopic use by asurgeon to controllably create with specificity a void within thevertebral body of a subject's vertebra.

It is another object of the present invention to provide a tissueexpansion device that is capable of selectively exerting sufficientforce in one or more directions to manipulate a tissue mass,particularly bone tissue.

Another object of the present invention is to provide a tissue expansiondevice that is capable of the controlled, measured and predictabledistracting of the vertebral endplates of a patient's vertebra fromwithin the vertebral body.

Another object of the present invention is to provide a tissue expansiondevice, which incorporates a selectively releaseable spreading assemblyor modular expansion member for correcting the positioning of tissue orbone. After the tissue or bone correction has been effected thespreading assembly can be released and left implanted in the patient tomaintain the correction.

Another object of the present invention is to provide a method forforming a space within tissue while employing a minimally invasivesurgical procedure.

Another object of the present invention is to provide a method formanipulating bone tissue in a directionally controlled and measuredmanner.

Another object of the present invention is to provide a method fordistracting the vertebral endplates of a patient's vertebra from withthe vertebral body.

Another object of the present invention is to provide a method forcorrecting the positioning of tissue or bone with a patient andimplanting a spreading assembly into the patient to maintain the tissueposition correction.

Another object of the present invention is to provide a method forproviding additional long term support for the vertebral body byinserting supporting material, such as bone cement or the like, into thespace formed by the device of the present invention. This object can beachieved after the device of the present invention has been used tocreate a space within the veterbral body and the spreading assembly hasbeen removed. Alternatively, this object can be achieved by insertingthe bone cement into the space within the vertebral body after thespreading assembly has been selectively detached from the shaft assemblyof the device. In this embodiment, the spreading assembly is left inplace within the vertebral body so as to provide additional supportalong with the bone cement for the vertebra. In every case, the sleeveportion of the present invention can serve as a conduit for introductionof the bone cement.

All of these objects are achieved by the use of the device and method ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of illustration only, withreference to the accompanying drawings.

FIG. 1 is a cross-sectional plan view of a first embodiment of thedevice of the present invention, which shows the mechanism configured inan expanded position.

FIG. 2 is a cross-sectional plan view of a first embodiment of thedevice of the present invention, which shows the mechanism configured ina closed position.

FIG. 3 is an isometric view of the mechanical detail of the modularspreading assembly of a second embodiment of the present invention inthe expanded position.

FIG. 4 is an isometric view of the mechanical detail of the modularspreading assembly of the embodiment of the present invention of FIG. 3shown in the closed position.

FIGS. 5A-C show plan, top and end views of the modular spreadingassembly of the embodiment of the present invention shown in FIGS. 3-4.

FIG. 6 is an isometric view of an alternative handle assembly of thepresent invention.

FIGS. 7A-B show a side and end view of a third embodiment of the deviceof the present invention in a closed (A) and open (B) position.

FIGS. 8A-B show a side and end view of a fourth embodiment of the deviceof the present invention in a closed (A) and open (B) position.

FIG. 9 shows a protective sheath enclosing another alternativeembodiment of the spreading assembly of the present invention.

FIG. 10 shows another alternative embodiment of the handle assembly ofthe present invention.

FIGS. 11A-11C show three non-limiting, alternative examples of aknob-type handle assembly for use with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The apparatus and method of the present invention can be adapted for usein a variety of surgical procedures which require precise tissuemanipulation by a surgeon. The following description and associatedFIGS. 1-11C are provided as non-limiting examples of the invention,which is defined with particularity only by the claims of the presentinvention.

As shown in FIGS. 1-10, a tissue manipulation device (10) is provided. Apreferred embodiment of the present invention is configured to beparticularly well-suited to the manipulation of bone in a subject. Byway of example, the device (10), as best shown in FIGS. 1-9, includesthree portions or assemblies which can be integrally formed orseparately fabricated prior to being joined to form the device (10).

The three assemblies, which together form the device (10), include ahandle assembly (12), a shaft assembly (14) and a spreading assembly(16). A proximal end (18) of the shaft assembly (14) is connected to thehandle assembly (12) and a distal end (20) of the shaft assembly (14) isconnected to the spreader assembly (16).

As earlier indicated, these three assemblies (12, 14, 16) can beintegrally formed or, alternatively, can be individually formed and thenconnected to form the whole device (10). It is also within the conceptof the present invention for the one or more of the assemblies to bereleasably connected one to the other.

In an embodiment where the three assemblies (12, 14, 16) are formed andsubsequently permanently connected one to the other, the connections maybe of any character known for connecting parts of a whole into one unit,to include, for example: gluing, soldering, welding, mechanicallyjoining by rivets or screws or the like or any other means forpermanently connecting parts one to the other.

If the three assemblies (12, 14,16) are releasably attached one to theother, any releasable attachment means known can be used, to include,for example: snap fittings, bayonet fittings, luer lock fittin0gs,threaded fittings, cotter-pin connections, plug and socket connections,or any other releasable attachment means. If the device (10) isintegrally formed, any manufacturing process known can be employed, toinclude extrusion molding, die-casting, tooling, or any other means offabricating such a device.

When the device (10) is configured to permit releasable attachment ofthe three assemblies (12, 14, 16) to each other, it is possible for theuser to attach alternative embodiments of any of the three individualassemblies (12, 14, 16). This feature of the invention permits each ofthe three assemblies (12, 14, 16) to separately have specificallydesigned embodiments that are configured for very specific uses or forindividual preferences of the using surgeon. Thus, one embodiment of thedevice (10) enables the user to customize the combination of the threeassemblies (12, 14, 16) to meet the particular requirements for aspecific surgical procedure.

As best shown in FIGS. 1-2, the handle assembly (12) can be configuredto operate as a scissor-like embodiment so as to provide ease ofhandling by a user during operation of the device (10). FIG. 1 providesa depiction of the scissor-like embodiment of the handle assembly (12)in the device-open configuration while FIG. 2 depicts this embodiment ina device-closed configuration. It is within the concept of the inventionto reverse the operable effect of the handle positions shown in FIGS. 1and 2 without departing from the concept of the invention. Thescissor-like embodiment of the handle assembly (12) depicted in FIGS. 1and 2 can include a first handle member (22) and a second handle member(24), each handle member (22, 24) having respectively a connecting end(26, 28) and a gripping end (30, 32).

Each of the connecting ends (26, 28) are movably connected one to theother by a handle member connector (34). In a preferred embodiment, thehandle member connector (34) is configured as a handle member pivot pin(36) although the handle member connector (34) can be configured asrotationally engaged portions of the first and second handle members(22, 24). Thus, the handle member connector (34) can be configured toinclude a pivot pin (36), a rotating ball-and-socket joint, a rotatingrim-and-groove joint, or any other connection design which permits theconnecting ends (26, 28) of the first and second handle members (22, 24)to be connected in a moveable relationship one to the other. The firstand second handle members (22, 24) can be biased into a closed or openrelationship one to the other by a biasing member (38), which can bereleasably attached to facilitate repair and replacement.

The handle members (22,24) can define an actuating arm portal (40) whichprovides for an arm anchor (42) defined within the second handle member(24). The portion of the portal (40) defined through the first handlemember (24) can be sized and configured to hold and restrict themovement of an actuating arm sleeve (44). The shaft assembly (14)includes the actuating arm sleeve (44) and the actuating arm (46). Theactuating arm sleeve (44) can be sized and configured to permit slidingpassage of the actuating arm (46). The actuating arm (46) at itsproximal end (48) can be releasable attached to the actuating arm anchor(42). Both the actuating arm (46) and the actuating arm sleeve (44) areconfigured to be in a sliding relationship, one within the other, and tobe of a respective fixed length such that the actuating arm (46) canslide to a position which extends beyond the distal end (50) of thesleeve (44).

Attached at the distal end of the actuating arm (52) is a spreadingassembly (16). The spreading assembly (16) can be sized and configure tofit within the sleeve (44) when the actuating arm (46) is fullywithdrawn into the sleeve (44). The spreading assembly (16) can bereleasable from the actuating arm to permit the surgeon to insert thespreading assembly into a bone, actuate the spreading assembly into anexpanded position, and, if desired, disconnect the spreading assembly soas to permit it to be left within the bone. This optional releasablefeature of the spreading assembly (16) also permits the device to beconfigured with different sizes and configurations of spreading assemblyprior to use.

The spreading assembly (16), as best seen in FIGS. 3, 4, and 5A-C, canbe configured to include at least one extending arm (56) that can be inpivotal relationship at one end with the actuating sleeve (44). Anysufficiently strong material compatible for use in surgical instrumentscan be used in the manufacture of the device. The extending arm (56) ispreferably manufactured of a rigid material to provide strength andreliable, consistent performance during operation. Conventionalspreaders, which can include flexible sleeves are incapable of providingthe even, consistent force during operation that is essential for safelymanipulating bone material. This especially important when manipulatingthe end plates of a vertebral body. At least one bracing member (58) isrotationally attached at one end to the actuating arm (46) androtationally attached at the other end to the proximal end of theextending arm (56). Due to the operational requirement of manipulatingbone, it is preferable that the bracing member be manufactured of rigidmaterial, however any material suitable for use in surgical instrumentscan be used if sufficiently strong. In operation, when the actuating arm(46) is extended distally beyond the confines of the sleeve (44), thebracing member (58) serves to exert a force on the extending arm (56) soas to force the spreading assembly into an open position. A lockingmechanism can be provided so as to releasably lock the spreadingassembly into position. This locking mechanism can be configured as anotch, slot, or other like means to fix the spreading assembly into anopen position. The locking mechanism can be selectively locked orunlocked.

To facilitate smooth operation of the spreading assembly (16), a guidebar (60) sized and configured to slidably move with the confines of aguide slot (62) can be provided. The guide slot (62) can define theforward most and reward most movement of the guide bar (60) and in sodoing control the degree of extension of the spreading assembly inoperation. The guide slot (62) can thus be sized to control the amountof extension possible for the spreading assembly (16). The distal mostportion of the extending arm (56) can be provided with a base plate(64), which can be pivotally attached thereto. The base plate (64) issized and configured to provide a contact surface (66) that in operationis brought into contact with the bone to be manipulated. This contactsurface (66) can provide a protective element to distribute the pressureexerted by spreading assembly across a broader surface of the bone beingmanipulated.

To provide visual feedback to the surgeon, the device (10) can bemanufactured such that at least a portion of the device is radiopaque.It is within the concept of the invention that only select portions ofthe device (10), such as, for example, the contact surface (66) or thebase plate (64) are manufactured or treated to include radiopaquematerial. Any method known in the art to manufacture or treat the device(10) so as to have a radiopaque quality can be employed withoutdeparting from the general concept of the present invention.

The first embodiment of the present invention described aboveillustrates the concept of the invention. It is, however, within thescope of the invention to configure the device (10) with a wide varietyof handle assemblies (12) that would serve to actuate the device bymovement of the actuating arm (46) with the actuating arm sleeve (44).Another non-limiting example of an alternative handle assembly (12) isshown in FIG. 6. This alternative handle assembly (12) can be configuredsimilar to the scissor-like embodiment shown in FIGS. 1-2 with theadditional feature of a handle locking assembly, generally shown at(68). The handle locking assembly (68) can be provided with a lockingcatch (70) similar to that typically found on a hemostat instrument. Thelocking catch (70) can be employed with a handle locking arm (72) thatis configured for releasably locking the handle assembly (12) to adesired open, partially open, or closed position as desired by the usingsurgeon.

Another embodiment of the invention can include an alternative handleassembly as shown in FIG. 10, which generally includes the basicfeatures of the handle assemblies discusses above, that is, opposingfirst and second handle members (22, 23), a handle member connector (34)and pivot pin (36), an actuating arm anchor (42) for securing the distalend of the actuating arm (46), and at least one biasing member (38). Thealternative handle assembly shown in FIG. 10 also includes theadditional feature of a grip stabilizing member (77), against which theusers' first thumb joint can rest during operation, and a controlledcompression assembly, generally shown at (78), which provides a meansfor the user to fine-tune control the compression of the two handlemembers. The controlled compression assembly (78) includes a threadedcompression shaft (79) that is rotatably connected to the second handlemember (23) by a shaft securing member(80). The threaded compressionshaft (79) slidably extends through a compression shaft bore (81)defined in the first handle member 22 and terminates in a manualcontroller stop (82). The manual controller stop (82) acts to limit theextreme movement of the manual controller (83), which iscorrespondingly-threaded and disposed around the threaded compressionshaft (79). In a preferred embodiment of this handle assembly, themanual controller (83) is configured as a thumb wheel for ease ofoperation. In operation, the user can manually compress the handlemembers (22, 23) together and, if desired, move or thread the manualcontroller (83) along the threaded compression shaft (79) to a positionthat holds the two handle members (22, 23) in the selected positionrelative one to the other. Alternatively, the handle members can bemoved toward or away from each other by simply manually turning themanual controller (83) so as to tighten or loosen the control memberagainst the outward bias of the first handle member (22), the bias beingprovided by the at least one biasing member (38).

Without departing from the general concept of the invention, the handleassembly (12) can be provided as a simple grip and control mechanism,such as a knob, in place of a multi-membered squeeze-actuated handle. Asbest shown in FIGS. 11A-11C, This alternative knob configuration can beprovided as a simply configured control knob (88), which can be providedin any form as is known in the art, to include, for example arotationally attached, longitudinally aligned knurled knob (88)employing a screw-type actuator (89) to advance or retract the actuatingarm (46) within the sleeve (44); the knob being knurled (90) or equippedwith one or more radially extending side grips (91), or equipped with acircumferentially disposed gripping ring (92), as is commonly used inthe art, for example as a common handle for a water faucet valve.Regardless of the configuration selected, the knob (88) embodiment ofthe handle assembly provides for the user a gripping element with amanual device actuator to selectively expand or retract the spreadingassembly (16) of the present invention in much the same way as the otherembodiments of the handle assembly (12).

Each of the alternative handle assembly embodiments discussed hereinwhen manually operated by a user results in the movement of theactuating arm (46) within the sleeve (44) such that the spreadingassembly (16) is expanded so as to manipulate tissue.

As best shown in FIGS. 7A-B and 8A-B, additional alternative embodimentsof the present invention can be provided which employ the same conceptof the earlier described embodiment with the modification of providing adual-scissor assembly, generally shown at (74), that permits the use oftwo bracing members (58) pivotally attached to the actuating arm (46) atthe proximal end and pivotally attached at a base plate pivot point(76). In FIGS. 8A-B, an alternative embodiment using two bracing members(58) attached at a single base plate pivot point is shown in both theclosed (A) and open (B) positions. In FIGS. 7-A-B, the alternativeembodiment is shown using two bracing members (58) attached at twodistinct pivot points (alternative embodiments provide a configurationwith the potential for increased leverage strength during the opening ofthe spreading assembly (16) as well as, in the case of FIGS. 7A-B, abroader base of support for the base plate (64).

The present invention preferably includes a means of protecting themechanism of the spreading assembly (16) from unwanted contact,entanglement, and interference with the tissue of a subject. On ingress,during operation, and on egress from the tissue-manipulation site withina subject, it is possible for surrounding tissue or bone to become soinvolved with the internal mechanism of the spreading assembly (16) thatthe device might be operationally impaired or rendered inoperablealtogether. As shown in FIG. 9, the present invention provides aprotective sheath (84) constructed of a highly flexible, high memorymaterial that tightly and closely overlays the entirety of the spreadingassembly (16) so as to provide a protective layer capable of keeping allunwanted tissue contact from the working mechanism of the spreadingassembly.

The sheath (84) can be constructed of any medically/surgicallyacceptable elastic formulation that can be easily stretched during fullexpansion of the spreading assembly (16) without losing its integrityand without causing extreme resistance to spreading and back pressure onthe spreading assembly. Further, the material used to fabricate thesheath (84) will have extremely good memory, that is shape-recoverycharacter, and as the spreading assembly is returned to its compact,non-spread configuration, the sheath will return to its tight, closerelationship to the more compact configuration of the spreading assembly(16). Thus, the sheath (84) will upon spreading of the spreadingassembly (16) provide protection of the mechanism and, upon return tothe non-spread configuration the sheath (84) will provide a smooth tightsurface around the spreading assembly so as to facilitate the easypassage of the spreading assembly from the subject when the user choosesto retract the device. The sheath (84) is preferably manufactured of apolyurethane material and will be circumferentially bonded to the sleeve(44) of the device at a bonding point (85) just before the spreadingassembly (16) exit from the sleeve (44). In either embodiment, thesheath (84) bonded to the sleeve (44) or bonded to the actuating arm(46), the mechanism of bonding can be by any secure and permanent meansknown in the art to include, but not limited to using adhesives, heatsealing, shrink film adhesion, or mechanical connection, such as, forexample a groove and circumferentially inserted securing ring (86).Alternatively, the sheath (84) can be bonded to the spreading assemblyat a point just before the spreading mechanism of the spreading assembly(16). For those embodiments of the present invention, where thespreading assembly can be released from the actuating arm and leftwithin the subject as a structural support for the bone that that hasbeen manipulated, the device can be configured to have a quickdisconnect (87) point between the actuating arm (46) and the spreadingassembly (16). Such a quick disconnnect can be provided by mechanicaldisconnect means, manufacture of a programmed break-away or shear pointfor a given torque, or any method of providing such a disconnection asis known in the art. The sheath (84) for such an embodiment remainsintact and in place around the spreading assembly (16).

The alternative configuration of the spreading assembly (16) shown inFIG. 9 is similar in design and assembly to that earlier described inFIGS. 7A and 7B with the adjustment that the two extending arms (56) andthe two bracing members (58) cross over each other respectively in ascissor-jack configuration. Each of the ends of the extending arms (56)and bracing members (58) terminate on two attachment points on the buttplate (64) in the same manner as the spreading assembly (16) embodimentshown in FIGS. 7A and 7B.

Each of the embodiments described above are provided for illustrativepurposes only and it is within the concept of the present invention toinclude modifications and varying configurations without departing fromthe scope of the invention that is limited only by the claims includedherewith.

1. A surgical apparatus for use in manipulating tissue of a subject, comprising: an elongated shaft assembly having a proximal end and a distal end, said elongated shaft comprising an actuating arm and an outer sleeve, said outer sleeve slidably circumscribing at least a portion of said actuating arm, a handle assembly attached to said proximal end of said shaft assembly, said handle member being attached to said shaft assembly and configured such that actuation of said handle assembly is capable of effecting movement of actuating arm within said outer sleeve, and a spreading assembly attached to said distal end of said shaft assembly, said spreading assembly comprising at least one bracing member and at least one extending arm and being at least partially surrounded by a protective sheath, said bracing member having a first end and a second end, said first end being rotationally attached to said actuating arm and said second end being rotationally attached to said extending arm, such that upon movement of said actuating arm, said bracing member is capable of radially displacing at least a portion of said extending arm, wherein said radially displaced extending arm when displaced is capable of contacting and manipulating said tissue.
 2. The surgical apparatus of claim 1, wherein said tissue is within the vertebral body of said subject.
 3. The surgical apparatus of claim 1, further comprising a base plate attached to said extending arm.
 4. The surgical apparatus of claim 3, wherein said extending arm has a proximally disposed arm first end and a distally disposed arm second end, said base plate being attached at said arm second end.
 5. The surgical apparatus of claim 4, wherein said base plate is rotationally attached to said extending arm.
 6. The surgical apparatus of claim 1, wherein said spreading assembly is releasably attached to said shaft assembly such that when said spreading assembly is selectively released from said shaft assembly, said sheath remains in place with said spreading assembly.
 7. The surgical apparatus of claim 5, wherein said spreading assembly can be locked in a position such that said base plate is radially displaced from said shaft assembly.
 8. The surgical apparatus of claim 1, wherein said bracing member is manufactured of rigid material.
 9. The surgical apparatus of claim 1, wherein said handle assembly comprises a first handle member and a second handle member.
 10. The surgical apparatus of claim 9, wherein said handle assembly further comprises a biasing member, said biasing member being configured to keep said first handle member apart from said second handle member.
 11. The surgical apparatus of claim 9, wherein said handle assembly further comprises a controlled compression assembly, which is capable of fine-tuned control of the compression of the two handle members.
 12. The surgical apparatus of claim 9, wherein said first handle member comprises a actuating arm anchor, said actuating arm being movably connected to said arm anchor.
 13. The surgical apparatus of claim 12, wherein said second handle member comprises an actuating arm portal, said arm portal being connected to said outer sleeve; such that when said first handle member and said second handle member are moved in relation one to the other, said actuating arm slidably moved within said outer sleeve through said actuating arm portal.
 14. The surgical apparatus of claim 1, wherein said spreading assembly comprises multiple extending arms and multiple bracing members.
 15. The surgical apparatus of claim 14, wherein said extending arms are rotationally connected to a base plate.
 16. The surgical apparatus of claim 15, wherein said base plate has two extending arms rotationally connected thereto at a single rotation point.
 17. The surgical apparatus of claim 15, wherein said base plate has two extending arms rotationally connected at separate respective rotation points.
 18. The surgical apparatus of claim 14, wherein said extending arms and said bracing members are aligned one to another in a scissor-jack configuration.
 19. The apparatus of claim 1, wherein at least two of the following are releasably connected one to the other, said shaft assembly, said handle assembly and said spreading assembly.
 20. The apparatus of claim 1, wherein said handle assembly is a knob-type assembly.
 21. The apparatus of claim 1, wherein said handle assembly further comprises a handle position lock.
 22. The apparatus of claim 1, wherein at least a portion of said device is radiopaque.
 23. The apparatus of claim 1, wherein said sleeve is so configured as to be capable of acting as a conduit for bone cement being injected into a space formed by said spreading assembly after removal of said actuating arm from said sleeve.
 24. A method of forming a space within a vertebral body of a subject, the method comprising: providing an apparatus according to claim 1, inserting said apparatus into the vertebral body of said subject, actuating the handle assembly so as to cause the spreading assembly to open and contact the interior bone material of the vertebral body, whereby said vertebral body has a space formed.
 25. The method of claim 24, wherein said inserting step is accomplished using minimally invasive surgical technique.
 26. The method of claim 24, where said spreader assembly of said apparatus according to claim 1 is disconnected and left within said vertebral body after said space is formed.
 27. The method of claim 24, wherein said spreading assembly is removed from said vertebral body after said space is formed.
 28. The method of claim 26, further comprising the step of filling said space formed with supporting material.
 29. The method of claim 27, further comprising the step of filling said space formed with supporting material. 